Institut für Physik - Humboldt-Universität zu Berlin and Max-Born-Institut
Publications>>Anomalous resonances of an optical microcavity with a hyperbolic metamaterial core
Anomalous resonances of an optical microcavity with a hyperbolic metamaterial core
E. Travkin, T. Kiel, S. Sadofev, K. Busch, O. Benson, and S. Kalusniak (2018)
Physical Review B 97:195133
Summary (expand/hide)
We embed a hyperbolic metamaterial based on stacked layer pairs of epitaxially grown ZnO/ZnO:Ga in a monolithic optical microcavity, and we investigate the arising unique resonant effects experimentally and theoretically. Unlike traditional metals, the semiconductor-based approach allows us to utilize all three permittivity regions of the hyperbolic metamaterial in the near-infrared spectral range. This configuration gives rise to modes of identical orders appearing at different frequencies, a zeroth-order resonance in an all-positive permittivity region, and a continuum of high-order modes. In addition, an unusual lower cutoff frequency is introduced to the resonator mode spectrum. The observed effects expand the possibilities for customization of optical resonators; in particular, the zeroth-order and high-order modes hold strong potential for the realization of deeply subwavelength cavity sizes.